hot spot n.
A region in a gene in which there is a high rate of mutation. Its existence depends on the size of the region concerned, the readiness with which the mutation can be detected, and the possibility that selection against mutants at that point is less than that against mutants elsewhere.
A volcanic area that forms as a tectonic plate moves over a point heated from deep within the Earth's mantle. The source of the heat is thought to be the decay of radioactive elements. The Hawaiian Islands formed as a series of hot spots. See more at tectonic boundary.
A place deep within the Earth where hot magma rises to just underneath the surface, creating a bulge and volcanic activity (see volcano). The chain of Hawaiian Islands (see Hawaii) is thought to have been created by the movement of a tectonic plate over a hot spot.